Hundreds of people have protested outside the high court in the city of Kano in northern Nigeria after a case against the pharmaceutical company Pfizer was adjourned.

The hearing was moved to September after the judge hearing the case failed to turn up.

Pfizer is best known for its Viagra drug

Three Nigerian families were given permission to sue Pfizer by the Kano high court in March after 11 children died, allegedly after taking part in a test for a new meningitis drug, Trovan.

Pfizer insists the drug was beneficial to most of the children who took part in the test and caused no harm. The families are asking for $100m in compensation from Pfizer.

Maimed

"The company should be made to compensate us. My child is now deaf and dumb for taking the Trovan," said Dauda Zango, a spokesman for the plaintiffs.

The affected children took part in the test during a meningitis epidemic in1996. The disease left thousands dead, and thousands more permanently disabled.

The hospital did not approve the tests

Kano hospital director

The families suing Pfizer are also claiming $100m
from the Nigerian Government for allowing the test to take place.

A nurse at the Infectious Diseases Hospital said that parents rushing their children in for treatment by the aid organisation Medecins San Frontieres were confused by the presence of people from Pfizer and unwittingly allowed Trovan to be tested on their children.

No consent

Pfizer said it did not get written permission from the parents because they were illiterate, but did say the tests were sanctioned by the Nigerian medical authorities.

But Dr Sadiq Wali, the medical director of the hospital, told the BBC that the letter of consent from the hospital's ethics committee, which the company showed to the US Government, must have been a fake as there was no such committee in place at the time.

Pfizer denies responsibility for the forgery.

Trovan has now been withdrawn from European and American markets after a number of Trovan patients developed serious liver problems. Some died.